There are already several developments in existence which serve to detect personal injuries. The majority of developments involve deriving corresponding measures from the impact design. This has the disadvantage of causing injury to the person. Furthermore, corresponding measures have to be implemented very quickly (in the microsecond range), which is also likely to lead to additional injury to the person.
DE602006001012T2 describes a system wherein a person is suitable to be detected via the analysis of two visual images (stereo camera). The analysis of two visual images has the disadvantage that the image becomes unrecognizable via droplets in case of rain. Furthermore, the visual detection of persons at night is extremely difficult.
A differentiation between moving persons and moving objects is also a problem. This is why a system is described in DE 10 2009 038 929 that calculates the speeds or sizes of objects via radar and camera by means of the temporal recording of distances to objects. However, this also has the disadvantage that a precise differentiation between person and object is not readily possible. Objects are suitable to overlap, thereby resulting in unusual sizes or movements. Furthermore, objects may take the dimensions of people, so that a differentiation is not suitable to be made.